Relationship between ovarian ultrasonographic findings on the seventh post-estrus day and plasma progesterone concentration, nutritional metabolic factors, and pregnancy outcome in dairy cows.

To improve the accuracy of ultrasonographic assessment of luteal function, we investigated the relationship between ovarian ultrasonographic findings on Day 7 (Day 1 = ovulation) and plasma progesterone (P4) concentration, nutritional metabolic factors, and pregnancy outcome. A total of 47 spontaneous estrus events were investigated in 38 lactating Holstein cows (artificial insemination, n = 31; embryo transfer, n = 16). Transrectal ultrasonography was performed on Days 0 and 7 to measure the pre-ovulatory follicle area on Day 0 and the luteal tissue area (LTA), luteal blood flow area (LBF), relative LBF (rLBF) (= LBF/LTA), and dominant follicle area (DFA) on Day 7. Blood samples were collected on Day 7 to measure plasma P4, insulin-like growth factor-I (IGF-I), insulin, and metabolites. Plasma P4 concentration was positively correlated with LTA but was not associated with LBF or rLBF. Plasma P4 concentration was positively correlated with blood glucose and IGF-I and negatively correlated with blood urea nitrogen and free fatty acid, and no significant relationship was found between the ultrasonographic findings of the corpus luteum (CL) and these blood metabolites. Pregnant cows had smaller DFA than non-pregnant cows. In conclusion, LTA measurement can help predict plasma P4 concentration, but it was difficult to detect variations in plasma P4 concentration in relation to changes in energy status by evaluating the CL ultrasonographically. A combined assessment of CL and first-wave dominant follicle may be important in evaluating fertility.

Effects of short-term dietary supplementation on the number of ovarian follicles, quantity and quality of oocytes, and in vitro embryo production in Japanese Black cows.

This study aimed to test the hypothesis that short-term supplementation with a high-energy diet promotes embryo production following ovum pick-up (OPU) in Japanese Black cows. After a period of adaptation to the maintenance diet, a 200% maintenance diet was fed to the high-energy diet group (HD group, n = 6) for four weeks, and a maintenance diet was fed to the other group (MD group, n = 6). OPU-in vitro fertilization (IVF) procedures were performed on days 14, 21, and 28; follicles and oocytes were counted and morphologically graded, and cultivable oocytes were cultured for in vitro maturation, fertilization, and culture. The mean plasma insulin concentrations on days 14 and 21 were significantly higher in the HD group than in the MD group (P < 0.05). The number of follicles observed at OPU, recovered oocytes, cultivable (Grades 1 to 4) oocytes, and the rate of degenerated (Grade 6) oocytes in the HD group were significantly higher than those in the MD group (P < 0.05). The proportion of cleaved oocytes was lower in the HD group than in the MD group (P < 0.05); consequently, there was no significant difference in the number of blastocysts obtained between the HD and MD groups. The present findings suggest that high-energy diets can promote follicular growth in parallel with an increase in plasma concentrations of insulin, but have a detrimental effect on the quality of oocytes with the OPU-IVF procedure in Japanese Black cows.

Possible causes and treatment strategies for the estrus and ovulation disorders in dairy cows.

The reproductive performance of dairy cows has declined, along with an increase in their milk yield. First-service conception rates in lactating dairy cows are often lower than 50%. The precise detection of estrus is an important factor in the reproductive management of dairy cows for successful fertilization and pregnancy. However, estrus expression has been decreasing in modern dairy cows, affecting the detection rate of estrus. In addition to estrus, a high incidence of ovulation disorders affects the fertility of dairy cows. To address these problems, it is necessary to understand the changes in the endocrine functions that underlie estrus and ovulation disorders, and to develop effective treatment strategies. Recent studies have revealed that neurokinin B and neurokinin 3 receptor signaling play important roles in the regulation of the secretion of gonadotropin-releasing and luteinizing hormones, suggesting a potential clinical avenue for the stimulation of gonadal function. In this review, I have discussed the problems in estrus and ovulation disorders in modern dairy cows as well as the possible applications of neurokinin 3 receptor agonists in the treatment of these disorders.

Intravaginal administration of estradiol benzoate capsule for estrus synchronization in goats.

Estrus synchronization requires multiple treatments of hormonal drugs, requiring considerable time and cost. The aim of the present study was to develop an estrus synchronization protocol using intravaginal administration of estradiol benzoate (EB) capsules in goats. Two types of capsules were prepared: an EB capsule that melted immediately after administration and a sustained-release (SR) EB capsule that dissolved slowly and reached a peak after 24 h. Goats with functional corpus lutea were intramuscularly treated with prostaglandin F2α (PG). At 24 h after PG administration, goats were administered 1 mg of EB solution intramuscularly (PG + 24IM; n = 6) or 1 mg of EB capsule intravaginally (PG + 24EB; n = 6). The SR EB capsule was administered intravaginally at the time of PG administration (PG + SR; n = 6). The control group (n = 6) received only PG. All groups showed estrus within 72 h after PG administration. The onset of estrus did not differ significantly between the PG + 24IM and PG + SR groups but was earlier than in the control group. Estradiol concentration in the PG + SR group peaked at 11.5 ± 6.1 h after EB and PG administration. Peak estradiol concentrations were not significantly different between the PG + 24IM and PG + SR groups (78.0 ± 25.8 and 64.0 ± 38.1 pg/ml, respectively), and were higher than the PG + 24EB and control groups (27.3 ± 8.8 and 14.6 ± 6.1 pg/ml, respectively). These results suggest that intravaginal administration of an EB capsule with a sustained-drug release base is applicable for estrus synchronization, as an alternative to intramuscular administration.

Intravaginal administration of progesterone using a new technique for sustained drug release in goats.

The objective of the present study was to develop and evaluate a sustained release vaginal progesterone (P4) capsule containing a mixture of mucoadhesive polymer and silicone fluid. Goats were administered a gelatin capsule containing 0.4 g of P4 mixed in silicone fluid and either a hydroxypropylmethylcellulose (HM) or polyaclil starch (PA) base. The mean plasma P4 concentrations at 2 and 12 h after administration were significantly higher in goats treated with PA capsules than in those with HM capsules. The plasma P4 concentrations in goats treated with HM capsules increased and remained above 1.0 ng/ml for 96 h after administration, whereas the plasma P4 concentrations in goats treated with PA capsules remained above 1.0 ng/ml for only 24 h after administration. In the next experiment, an HM capsule was attached to a silicone device and inserted in the vagina for 10 days. The plasma P4 concentration remained similar to that of the natural luteal phase for 9 days. These results suggest that a mixture of mucoadhesive polymer and silicone fluid has the potential to be applied clinically as a sustained release base for estrus synchronization or hormonal therapy.

The efficacy of a newly developed neurokinin 3 receptor agonist B21-750 on luteinizing hormone secretion in cycling goats.

This study aimed to investigate the efficacy of a newly developed NK3 receptor agonist (B21-750) on the secretion of luteinizing hormone (LH) in association with ovarian steroid hormones during the follicular phase (FP, n = 5) and luteal phase (LP, n = 5) of Shiba goats. The FP group was treated with both prostaglandin F2α and progesterone-controlled internal drug release (CIDR) inserts for 10 d, and B21-750 (200 nmol) was injected 12 h after removing the CIDR. Meanwhile, the LP group received B21-750 injections on a day during the mid-luteal phase. LH secretion increased at 1 h after B21-750 injection in both groups. The percent changes in the area under the curve of LH was higher during the hour after injection than during the hour before injection in both groups. Thus, this study demonstrated that B21-750 induces rapid LH secretion for a short period during both the follicular and luteal phases.

Effect of repeated adrenocorticotropic hormone administration on reproductive function and hair cortisol concentration during the estrous cycle in goats.

Measurement of the cortisol concentration in hair has been used as an index of chronic stress in several species including humans, wildlife and domestic animals. However, how accurately the cortisol concentration in hair reflects the changes in circulating cortisol concentrations has not been well documented. The objective of the present study was to examine the effect of repeated adrenocorticotropic hormone (ACTH) administration on the reproductive function during the estrous cycle and hair cortisol concentrations in goats. In experiment 1, goats were administered ACTH (0.625 IU/10 kg of body weight, n = 6) or saline (n = 6) intramuscularly once a day for 7 days on Day 11-17 of the estrous cycle (day 0 was the day of ovulation). In experiment 2, goats were administered ACTH (0.625 IU/10 kg of body weight, n = 6) or saline (n = 6) intramuscularly twice a day on Day 11-24 of the estrous cycle. Blood samples were collected 0, 0.5, and 6 h after first administration to determine the circulating cortisol concentrations. Hair was clipped at 0, 1, and 2 months after the start of administration. In both experiments, the plasma cortisol concentration increased at 0.5 h and returned to baseline at 6 h after ACTH administration. During the experiments, estrus was observed in most animals in ACTH and saline groups (6/6 and 4/6 in experiment 1 and 5/6 and 6/6 in experiment 2, respectively) and ovulation was observed in all goats examined. However, the number of ovulatory follicles was significantly different between the ACTH and saline groups, and the maximal diameter of ovulatory follicles tended to be different (P = .07) between the ACTH and saline groups. In experiment 1, the hair cortisol concentration was not influenced by the ACTH administration throughout the sampling period. In experiment 2, the hair cortisol concentration in the ACTH group was greater at 1 month after administration than the pre-administration value, but was not significantly different at 2 months. These results suggest that repeated ACTH administration affects the development and ovulatory process of ovarian follicles and analysis of the hair cortisol concentration can be used for assessing relatively long-term changes in cortisol concentration in the circulation.

Evaluation of criteria for optimal time AI postulated by estrous signs in lactating dairy cows kept in tie-stalls.

Relaxation of the intravaginal part of the uterus is obvious around 6 to 18 h before ovulation, and this is considered the optimal time for artificial insemination (AI), as demonstrated in recent studies. Estrous signs have been suggested as useful criteria for determining the optimal time for AI. Therefore, this study evaluated the usefulness of estrous signs, particularly the relaxation of the intravaginal part of the uterus, as criteria for determining the optimal time for AI. A Total of 100 lactating Holstein-Friesian cows kept in tie-stall barns were investigated. AI was carried out based on the criterion for the optimal time for AI (optimal group), and earlier (early group) and later (late group) than the optimal time for AI, determined on the basis of estrous signs. After AI, ovulation was assessed by rectal palpation and ultrasonographic observation at 6-h intervals. For 87.5% (35/40) of cows in the optimal group, AI was carried out 24-6 h before ovulation, which was previously accepted as the optimal time for AI. AI was carried out earlier (early group) and later (late group) than optimal time for AI in 62.1% (18/29) and 71.0% (22/31) of cows, respectively. The conception rate for the optimal group was 60.0%, and this conception rate was higher than that for the early group (44.8%) and late group (32.2%), without significance. Further, the conception rate of the optimal group was significantly higher than the sum of the conception rates of the early and late groups (38.3%; 23/60) (P < 0.05). These results indicate that the criteria postulated, relaxation of the intravaginal part of the uterus and other estrous signs are useful in determining the optimal time for AI. Furthermore, these estrous signs enable the estimations of stages in the periovulatory period.

Effect of investigational kisspeptin/metastin analog, TAK-683, on luteinizing hormone secretion at different stages of the luteal phase in goats.

This study aimed to examine the response of luteinizing hormone (LH) secretion and ovarian steroid profile to TAK-683, an investigational metastin/kisspeptin analog, through treatment during different stages of the luteal phase in goats. Nine cycling Shiba goats (4.4 ± 2.3 years old) were assigned to early luteal phase (ELP, n = 4), mid-luteal phase (MLP, n = 4), and control (n = 5) groups. The ELP and MLP groups were administered 50 µg of TAK-683 intravenously on either day 5 or between days 7-14 after ovulation, respectively. The control group received vehicle between days 7-14 after ovulation. Blood samples were collected at 10-min (2-6 h), 2-h (6-24 h), and 24-h (24-96 h) intervals after treatment. Significant increases in plasma LH concentration were detected during the periods of 3 to 5 h and 2 to 5 h in the ELP and MLP groups, respectively. Estradiol concentrations continuously increased with the rise of basal LH secretion after TAK-683 treatment in two goats of the ELP group with a surge-like release of LH, but not in the goats without LH surge, i.e. the MLP and control group ones. Plasma progesterone concentration and the lengths of estrous cycle in all groups did not change significantly from the time before and after treatment. Present findings indicate that the responses of LH and ovarian steroids to treatment with TAK-683 depend on the stage of the luteal phase of the estrous cycle. We suggest that the stimulatory effects of TAK-683 on LH secretion are reduced in the process leading to the mid-luteal phase in cycling goats.

An administration of TAK-683 at a minimally effective dose for luteinizing hormone stimulation under the absence of the ovary induces luteinizing hormone surge in ovary-intact goats.

The present study aimed to evaluate hormonal responses and their association with the TAK-683 blood concentrations in goats administered TAK-683 at a low dose, which had been previously determined as the minimally effective dose for luteinizing hormone (LH) stimulation in ovariectomized goats. In Experiment 1, 5 µg of TAK-683 treatment had no significant stimulatory effect on LH secretion in ovariectomized Shiba goats (n = 4). In Experiment 2, cycling goats received the treatment of prostaglandin F2α and progesterone-releasing controlled internal drug releasing (CIDR) to induce the follicular phase, then they were treated with 5 µg of TAK-683 (hour 0) intravenously (n = 4, IV) or subcutaneously (n = 3, SC) or with vehicle intravenously (n = 4, control) at 12 h after CIDR removal. Blood samples were collected at 10-min (-2-6 h), 2-h (6-24 h), or 6-h (24-48 h) intervals. Ovarian ultrasonographic images were assessed daily to confirm ovulation after the treatment. A surge-like release of LH was immediately observed after injection in all animals in the IV (peak time: 4.2 ± 0.6 h, peak concentration: 73.3 ± 27.5 ng/ml) and SC (peak time: 4.6 ± 0.4 h, peak concentration: 62.6 ± 23.2 ng/ml) groups, but not in the control group. Ovulation was detected within 3 days after TAK-683 injection in all animals in the IV and SC groups, and the interval period from TAK-683 administration to ovulation in the IV group was significantly (P < 0.05) shorter than that of the control group. No significant changes were observed between the IV and SC groups in terms of luteal diameter and blood progesterone levels after ovulation. The present findings suggest that the involvement of one or more ovarian factor(s) is indispensable for a TAK-683-induced LH surge leading to ovulation in goats.

Video tracking analysis of behavioral patterns during estrus in goats.

Here, we report a new method for measuring behavioral patterns during estrus in goats based on video tracking analysis. Data were collected from cycling goats, which were in estrus (n = 8) or not in estrus (n = 8). An observation pen (2.5 m × 2.5 m) was set up in the corner of the female paddock with one side adjacent to a male paddock. The positions and movements of goats were tracked every 0.5 sec for 10 min by using a video tracking software, and the trajectory data were used for the analysis. There were no significant differences in the durations of standing and walking or the total length of movement. However, the number of approaches to a male and the duration of staying near the male were higher in goats in estrus than in goats not in estrus. The proposed evaluation method may be suitable for detailed monitoring of behavioral changes during estrus in goats.

Progesterone profiles in the caudal vena cava and jugular vein in response to pulsatile luteinizing hormone stimulation induced by GnRH treatment during the mid-luteal phase in lactating dairy cows.

The aim of this study was to examine whether increased frequency of luteinizing hormone (LH) pulses influences luteal progesterone (P4) secretion by measuring progesterone concentrations at the secreted (caudal vena cava) and circulating levels (jugular vein) in lactating dairy cows. Cows received six intravenous administrations of 2.5 µg of GnRH (gonadorelin acetate, n=4) or 2 ml saline (n=3) at 1-h intervals on 12.4 ± 0.4 (mean ± SE) days after ovulation. Blood samples were collected from the caudal vena cava and jugular vein every 12 min for 12 h (6 h before and after treatment). During the 6 h after treatment, frequency of LH pulses (5.3 ± 0.3 and 3.0 ± 0.0 pulses/6 h) and mean LH concentration (0.50 ± 0.06 and 0.38 ± 0.05 ng/ml) were greater (P<0.05) in GnRH-treated cows than in saline-treated cows. Mean P4 concentration and amplitude of P4 pulses in the caudal vena cava during the 6 h after treatment were greater (P<0.05) in GnRH-treated cows than in saline-treated cows, but the frequency of P4 pulses was not different between the groups. Mean P4 concentration in the jugular vein during the 6 h after treatment was also higher (P<0.05) in GnRH-treated cows than in saline-treated cows (7.0 ± 1.3 and 5.4 ± 0.9 ng/ml). These results indicate that the increased frequency of LH pulses stimulates progesterone secretion from the functional corpus luteum and brings about higher P4 concentrations in the circulating blood in lactating dairy cows.

Changes in plasma progesterone levels in the caudal vena cava and the jugular vein and luteinizing hormone secretion pattern after feeding in lactating and non-lactating dairy cows.

The present study was designed to assess progesterone profiles at the secreted (caudal vena cava) and circulating levels (jugular vein) and luteinizing hormone (LH) secretion pattern in lactating and non-lactating cows with reference to feeding. Four lactating and four non-lactating cycling Holstein cows were examined. Blood samples were collected simultaneously from the caudal vena cava (via a catheter inserted from the coccygeal vein) and the jugular vein every 15 min for 12 h (0500-1700 h) during the functional luteal phase. Cows were fed 50% of the daily diet 6 h after the start of blood sampling. During the 12-h sampling period, mean progesterone concentrations in the caudal vena cava did not differ between lactating and non-lactating cows (49.0 ± 2.9 and 53.3 ± 3.7 ng/ml; mean ± SE), whereas mean progesterone concentrations in the jugular vein in lactating cows were higher than those in non-lactating cows (6.4 ± 0.1 and 5.6 ± 0.1 ng/ml, P < 0.001). Lactating cows had a higher frequency of LH pulses than non-lactating cows (7.0 ± 0.7 and 4.3 ± 0.9 pulses/12 h, P<0.05). The influence of feeding was not observed on LH profiles but was observed on progesterone profiles in both veins. Progesterone concentrations in the caudal vena cava increased after feeding in both groups. Progesterone concentrations in the jugular vein decreased after feeding in lactating cows but not in non-lactating cows. These results indicate the difference in feeding-related changes in progesterone dynamics between lactating and non-lactating cows.

Exposure to estrogen mimicking the level of late pregnancy suppresses estrus subsequently induced by estrogen at the level of the follicular phase in ovariectomized shiba goats.

A high-estrogen environment during late pregnancy is suspected to cause postpartum silent ovulation, and progesterone (P4) is suggested to recover estrus. However, few attempts have been undertaken to elucidate the influence of these steroids on estrus by analyzing hormonal profiles. We investigated estrus and luteinizing hormone (LH) surges in ovariectomized goats (n=6) assigned to three treatments in a cross-over design. In groups 1 and 2, 200 µg/kg body weight/day estradiol benzoate (Dose-200 E2B) was administered for 14 days concurrent with P4 for 11 days, while in the control, saline solution and P4 were administered likewise. Ten days after the final administration of Dose-200 E2B, group 2 was treated with P4 for 8 days, and all groups were treated with 2 µg/kg body weight E2B (Dose-2 E2B) 20 days after the final administration of Dose-200 E2B (or saline solution). The proportion of cases expressing estrus after the administration of Dose-2 E2B was smaller (P<0.01) in group 1 than in the control (1/6, 3/6 and 6/6; groups 1 and 2 and the control, respectively). The proportions of cases generating LH surges did not differ (P>0.1) among the groups (5/6, 5/6 and 6/6; groups 1 and 2 and the control, respectively), but the peak concentrations in groups 1 and 2 (26.2 ± 14.7 and 11.3 ± 6.7 ng/ml) were lower (P<0.01) than those in the control (67.8 ± 19.4 ng/ml). These results demonstrated that elevation of plasma estrogen mimicking late pregnancy inhibits the subsequent estrus induced by estrogen simulating the follicular phase.

Differential effects of continuous exposure to the investigational metastin/kisspeptin analog TAK-683 on pulsatile and surge mode secretion of luteinizing hormone in ovariectomized goats.

The aim of the present study was to determine if the estradiol-induced luteinizing hormone (LH) surge is influenced by the constant exposure to TAK-683, an investigational metastin/kisspeptin analog, that had been established to depress the pulsatile gonadotropin-releasing hormone (GnRH) and LH secretion in goats. Ovariectomized goats subcutaneously received TAK-683 (TAK-683 group, n=6) or vehicle (control group, n=6) constantly via subcutaneous implantation of an osmotic pump. Five days after the start of the treatment, estradiol was infused intravenously in both groups to evaluate the effects on the LH surge. Blood samples were collected at 6-min intervals for 4 h prior to the initiation of either the TAK-683 treatment or the estradiol infusion, to determine the profiles of pulsatile LH secretion. They were also collected at 2-h intervals from -4 h to 32 h after the start of estradiol infusion for analysis of LH surges. The frequency and mean concentrations of LH pulses in the TAK-683 group were remarkably suppressed 5 days after the start of TAK-683 treatment compared with those of the control group (P<0.05). On the other hand, a clear LH surge was observed in all animals of both groups. There were no significant differences in the LH concentrations for surge peak and the peak time of the LH surge between the TAK-683 and control groups. These findings suggest that the effects of continuous exposure to kisspeptin or its analog on the mechanism(s) that regulates the pulsatile and surge mode secretion of GnRH/LH are different in goats.

Effects of intravaginal administration of prostaglandin F2α on luteolysis and subsequent estrus in Shiba goats (Capra hircus).

This study examined the effects of intravaginal administration of prostaglandin F2α (PGF2α ) on luteolysis and subsequent estrus in cycling goats. Goats with functional corpus lutea received one of five treatments: 2 mg of PG intramuscularly (IM2 × 1; n = 6), 2 mg of PGF2α intravaginally (IVG2 × 1; n = 7), 4 mg of PGF2α intravaginally (IVG4 × 1; n = 7), and 1 or 2 mg of PGF2α intravaginally 8 h apart (IVG1 × 2 group; n = 6 and IVG2 × 2; n = 8). Blood samples were collected at 24-h intervals from 0 to 7 days after PGF2α administration. Estrus was checked twice daily during the experiment. The proportion of goats with complete luteolysis (reduction of progesterone concentrations to <1 ng/mL until 48 h after treatment) in the IVG2 × 1 group (28.6%) was significantly lower than in the other groups (IM2 × 1; 100%, IVG4 × 1; 57.1%, IVG1 × 2; 87.5%, IVG2 × 2; 100%, respectively). For goats completing luteolysis, there was no significant difference in the onset and duration of estrus among the groups. These results suggest that intravaginal administration of PGF2α can be applied as an alternative to intramuscular administration.

Evaluation of prepartum and postpartum stress by measuring hair cortisol concentrations of Holstein dairy cows and their calves and its relationship to calving conditions and health status.

Periparturient stress can have long-term negative effects on both dairy cows and their calves and may contribute to lower productivity. The purpose of this study was to determine how periparturient stress is related to differences in calving difficulty and health status by measuring hair cortisol concentration in periparturient dairy cows and their calves. Calving environment (calving pen, tie stall, and group paddock), calving difficulty, calving progress, health status, and calf weight were recorded, and tail hair from 25 of the cows and their calves was collected at calving and 1 month after calving to measure hair cortisol concentration. There were no significant correlations between hair cortisol concentration and calving environment, calving difficulty, calf weight gain rate. Hair cortisol concentrations at calving were significantly higher in cows with oversized calves or twin births than in cows with normal-sized singleton calves (4.2 ± 2.2 pg/mg vs. 2.1 ± 1.5 pg/mg, P<0.05). Cows with clinical disease within one month of calving had significantly higher levels of hair cortisol one month after calving compared to healthy cows (3.8 ± 1.1 pg/mg vs. 2.3 ± 1.9 pg/mg, P<0.05). Calves with clinical disease within the first month after birth tended to have higher hair cortisol levels at birth than healthy calves (4.7 ± 2.4 pg/mg vs. 3.2 ± 0.9 pg/mg, P<0.1). These results suggest that calving of oversized calves and twin births and suffering clinical diseases can cause more stress for cows during the periparturient period.

Effect of linearly polarized microwaves on nanomorphology of calcium carbonate mineralization using peptides.

Microwaves are used for diverse applications such as mobile phones, ovens, and therapy devices. However, there are few reports on the effects of microwaves on diseases other than cancer, and on physiological processes. Here, we focused on CaCO3 mineralization as a model of biomineralization and attempted to elucidate the effect of microwaves on CaCO3 mineralization using peptides. We conducted AFM, ζ potential, HPLC, ICP-AES, and relative permittivity measurements. Our findings show that microwaves alter the nanomorphology of the CaCO3 precipitate, from sphere-like particles to string-like structures. Furthermore, microwaves have little effect on the mineralization when the mineralization ability of a peptide is high, but a large effect when the precipitation ability is low. Our findings may be applicable to not only the treatment of teeth and bones but also the development of organic-inorganic nanobiomaterials. This methodology can be expanded to other molecular/atomic reactions under various microwave conditions to alter reaction activity parameters.

Profiles of ovarian steroids, luteinizing hormone and estrous signs from luteolysis to ovulation in lactating and non-lactating dairy cows.

The aims of the present study were to investigate the profiles of ovarian steroids and luteinizing hormone (LH) and the appearance of estrous signs in relation to luteolysis and ovulation in lactating and non-lactating cows and to examine the influence of lactation on those observations. Five lactating (daily milk yield of 28.4 ± 3.2 kg; mean ± SD) and five non-lactating cycling Holstein cows were examined. Their ovaries were monitored by ultrasonography daily during one estrous cycle. Blood samples were collected daily and then at 3-h intervals after luteolysis until ovulation. Estrous signs in terms of behavior, the vulva and the vagina were checked at 8-h intervals after luteolysis until ovulation. Profiles of progesterone, estradiol-17ß and LH did not differ between the groups. There were no differences in the interval from luteolysis to ovulation (4.6 ± 0.5 and 4.2 ± 0.8 days) and the interval from the estradiol-17ß peak to ovulation (34.2 ± 4.5 and 30.6 ± 3.9 h) between lactating and non-lactating cows. The interval from the peak of the LH surge to ovulation was 27 h in all cows examined. Appearance of estrous signs did not differ between the groups. The vaginal estrous signs were observed conspicuously in all cows examined, but the behavioral signs were not observed in 20.0% of the cows. The duration of behavioral signs (41.3 ± 23.6 h) was shorter (P<0.05) than that of the vagina (68.9 ± 25.4 h). These results imply that lactation might not interfere with the hormonal profiles from luteolysis to ovulation.

Changes in the C-reactive protein and 13,14-dihydro-15-keto-prostaglandin F2α concentrations of uterine lavage samples after the administration of povidone-iodine in cows.

Changes in the C-reactive protein (CRP) and 13,14-dihydro-15-keto-prostaglandin F2α (PGFM) concentrations of uterine lavage fluid were examined in cows given an intrauterine povidone-iodine (PI) infusion. The mean polymorphonuclear leukocyte (PMN) ratios (the ratio of PMN to total cells) and CRP concentration of uterine lavage fluid on the day after the treatment were significantly (P<0.05) greater in the PI infusion group (PMN: 53.0 ± 32.7%, CRP: 50.2 ± 32.3 ng/mL) than in the non-treatment control group (PMN: 7.9 ± 21.9%, CRP: 17.2 ± 5.9 ng/mL), whereas there was no significant difference in the mean PGFM concentration between the two groups. The present findings suggest that the uterine CRP level is a useful biomarker of local uterine inflammation in cows.